Method of removing nicotin from tobacco.



I UNITED STATES PATENT OFFICE.

RALPH SAYRE AND ELIAS YANOVSKY, OF WASHINGTON, DISTRICT OF COLUMBIA METHOD OF REMOVING NICOTIN FROM TOBACCO.

No Drawing.

To all whom it may concern Be it known that we, RALPH SAYRE and ELIAS YANOVSKY, both citizens of the United States, and residents of the city of Washington, District of Columbia, have invented certain new and useful Improvements in Methods of Removing Nicotin from Tobacco; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The invention relates to a method of improving tobacco by removing the nicotin therefrom, and has for its object to provide a simple, cheap and efiicient procedure, whereby the nicotin alone, or the nicotin and part of the proteins, which latter are more or less objectionable, may be removed from the tobacco, without afiecting or appreciably altering the other normal constituents of the tobacco which are regarded as indispensable to the maintenance of the fragance, flavor and combustibility of the tobacco, such constituents comprising certain organic acids or their salts, nitrates, waxes, resins, esters and other organic compounds, the chemical nature of which is but little known.

To these ends, the invention comprises the treatment of the tobacco with a solvent of such nature and character that it removes only the nicotin and protein constituents of the tobacco, separating the tobacco from the solvent and finally eliminating the nicotin from the solvent, preferably by precipitation by means of a suitable acid or salt and filtering. The preferred form of the solvent is a solution containing all the soluble constituents of tobacco, except nicotin and proteins, in quantities, which are determined, as hereinafter explained, by the relative amounts of tobacco and solvent used, so that when the tobacco is treated With the infusion the nicotin only, or the nicotin and part of the proteins will be removed by the solvent or liquid infusion, and after the latter has been separated from the tobacco, the nicotin may be separated from the infusion, leaving the latter in proper condition for the treatment of a new batch of tobacco, the series of operations being cyclical and the single infusion, with proper additions of water to make up the losses due to absorption of the infusion by the tobacco, can be used repeatedly and in Specification of Letters Patent.

Patented Feb. 11, 1919.

Application filed May 16, 1918. Serial No. 234,998.

definitely for selectively isolating or removing the nicotin from successive batches of tobacco, the extracted nicotin being separated from the infusion after each fresh batch of tobacco has been treated.

In carrying out the improved process, it is necessary first to prepare a standard infusion or solvent, which shall contain the soluble constituents of tobacco, in substantially the necessary and desired amounts, with the single exception of nicotin, of which the infusion is free. Such standard infusion may be prepared synthetically, provided the soluble constituents of the tobacco to be treated can be accurately determined. Ordinarily, however, the infusion will be prepared by soaking tobacco or tobacco waste, such as stems, stalks, ground leaves and the like, in water, removing the tobacco therefrom, adding to the extract an amOunt of water equal to the amount of extract retained by the tobacco, and repeating the procedure with successive portions of fresh tobacco or tobacco waste until the concentration of the solution undergoes no further change, and eliminating the nicotin from the infusion by addition of a reagent containing a suitable acid radical, such for example, as tannic acid, picric acid, molybdic acid, or the soluble salts of these acids, either after each extraction or preferably after the final extraction. After the precipitated nicotin has been separated from the infusion, the latter is in proper condition for treating tobacco commercially for the purpose of removing the nicotin, and. as indicated, also a portion of the proteins 7 therefrom.

For the purpose of illustrating the preparation of the solvent or infusion, which is capable of removing the nicotin (and in part the proteins) from tobacco, without affecting the other soluble constituent-s thereof, let it be assumed that ten parts by weight of the solvent be used for each part by weight of the tobacco treated. Furthermore, in order to simplify the illustration, small quantities of tobacco and infusion will be indicated and only two classes of soluble constituents of tobacco, which enter into and form a component part of the infusion will be considered, to wit, the nitrates and citrates, but it will be understood that tlie procedure and conditions as outlined in respect of the nitrates and citrates apply in like manner to the other soluble constituouts, and also that the proportions of tobacco and extract are merely exemplary. It is assumed that the tobacco contains 1.5% nitrates and 2% of nicotin citrate. In preparing the infusion, each extraction is performed upon say 100 grams of tobacco with 1 liter of solvent, the solvent in the first instance being water. It is also assumed that the treated tobacco retains its own weight of the solvent. The first extraction, in which water is used as a solvent, results in a tobacco containing .2 grams of nicotin citrate, .15 grams of the nitrates, which is con tained in the portion of the solution which wets the tobacco. The infusion or liquid solvent when separated from the tobacco will contain 1.8 grams of nicotin citrate and 1.35 grams of nitrates. If this solution be treated with a requisite portion of sodium tannate or other suitable precipitant for nicotin dissolved in 100 grams of water, the nicotin citrate is converted into nicotin tannate, and a chemically equivalent amount of sodium citrate is evolved, the nicotin tannate being precipitated and the sodium citrate remaining in solution. In order to simplify the calculation, let it be assumed that 1.8 grams of nicotin citrate yields 1 gram of sodium citrate upon the addition of sodium tannate, as indicated. This represents the first stage of the preparation of the solvent or liquid infusion, which latter after filtering off the precipitate is in condition for treatment of an additional portion of tobacco, that is to say, there will be 1 liter of water containing 1.35 grams of nitrates and 1 gram of sodium citrate. Since the additional 100 grams of tobacco which is extracted with this liquid solvent contains 1.5 grams of nitrates, and th of theftotal amount remains in the tobacco, due to the wetting of the latter by the liquid, the second batch of extracted tobacco will contain th of 2.85 grams of nitrate, and it will,

.of course, retain also .1 gram of sodium citrate. The remaining .9 grams of sodium citrate are retained in the extract or infusion and as 1.8 grams of nicotin citrate have again been added to the infusion, the subsequent action of the precipitant yields a solution which contains .9 plus 1 gram sodium citrate. Consequently the extraction of the third quantity of fresh tobacco will yield an infusion containing 1.8 grams of nicotin citrate, 1.71 grams of sodium citrate, 3.66 grams of nitrates. After the nicotin has been precipitated from the extract, the latter contains 2.71 grams of sodium citrate, and 3.66 grams of nitrates.

This indicates that the nicotin-citrate contentof the extracted tobacco will always be .2 grams in 100 grams of tobacco, that the amount of nitrates and sodium citrate in the solution, and consequently the amount of each retained by the extracted tobacco, in

creases, so that each successive portion of tobacco treated brings the solution nearer the desired standard, in which the proportion of the nitrates in the solution at the completion of each extraction will be the same as that in an equal weight of tobacco. Assume that the amount of nitrates in the solvent has reached the value of 13.5 grams, viz., nine times the amount in the original tobacco; then in the next extraction, the total amount of nitrates in the mixture of tobacco and solvent will be 15 grams (13.5+1.5) and, after removing the tobacco, th of the nitrates (1.5 grams) will remain in the tobacco, which will thus be left unaltered with respect to nitrates and the V extract will still contain 13.5 grams. In other words, the solvent thereafter will contain a fixed quantity of 13.5 grams of nitrates per liter of water.

The same considerations apply in respect of the sodium citrate. Assume that the solvent contains the citrate to the extent of 10 grams per liter of water. In the next extraction, 1 gram is left in the tobacco replacing the 1.8 grams of nicotin citrate which are always removed by the solvent from the tobacco, and which, in turn, yield by the action of sodium tannate, each, time, 1 gram of sodium citrate. When this point is reached, the solvent is automatically maintained with the fixed content of 10 grams of sodium citrate per liter of water, and the tobacco treated therewith will always retain 1 grain of sodium citrate in each 100 grams of tobacco, which is the chemical equivalent of the 1.8 'grams of nicotin citrate removed from the tobacco, and this relation insures that the amount of combined citric acid in the tobacco is kept intact. It can readily be seen from the discussion that, in the process of preparation of the solvent, nicotin need not be removed after each extraction but may be allowed to accumulate in the solution until the latter reaches a fixed concentration (in the illustration given 18 grams nicotin The elimination of nicotin and, part of the proteins is now brought about citrate).

by addition of the required amount of the precipitant leaving the solvent ready for treating tobacco commercially and may be used indefinitely for extracting successive batches of tobacco and removing therefrom only the nicotin and some of the proteins. The conditions indicated in respect of the nitrates and the citrates also apply to the other soluble constituents and sparingly soluble substances of the tobacco taken up by the infusion.

Assuming that the standard infusion or solution has been prepared as indicated, in treating the tobacco to remove the nicotin commercially, the tobacco is immersed and soaked in say substantially ten times its weight of the standard infusion or solution. All of the nicotin will go into solution and constitute a part of the infusion. The tobacco is then removed from the infusion and as much as possible of the liquid remaining in the tobacco is separated therefrom, by pressing the tobacco, and the expressed liquid restored to the infusion. If it be assumed that the tobacco will retain approximately its own weight of the liquid infusion, which, however, disappears so far as the liquid portion thereof is concerned when the tobacco is subsequently dried, this leaves only th of the original nicotln in the tobacco, which is practically negligible, but also leaves all of the other normal constituents of the tobacco intact and unaltered and supplies to the tobacco in lieu of the nicotin salt, which was removed, a quantitative equivalent of a salt or free acid, depending upon the particular character of precipitant used for removing the extracted nicotin from the infusion. After each extraction, the infusion is brought to its original volume by the addition of an amount of water equal to that of the infusion adhering to the tobacco treated. This quantity of water may be added to the infusion at the same time the precipitant is added thereto, and, as heretofore indicated, this additional amount of water may be used as the vehicle or solvent for the precipitant, such as tannic acid or sodium or potassium tannate, or any other suitable precipitant as hereinbefore indicated.

The effect of adding the precipitant to the separated infusion is to throw down the nicotin as a precipitate, which is-removed by the ordinary methods of filtration, or by any other suitable means, leaving the infusion in proper condition for removing the nicotin from a fresh portion of tobacco.

As hereinbefore indicated, the operations are cyclical and involve no material losses after the standard infusion has been prepared, as the latter is used over and over again for extracting the nicotin from successive batches of tobacco, in which the nicotin is replaced by a salt or acid, which either improves the quality of tobacco, or is practically innocuous. The process therefore not only results in the practical denicotinizing of the tobacco, without altering the other normal constituents thereof, but also offers a cheap and effective source of nicotin salts, which have commercial value and from which nicotin may be recovered by any of the well known methods. While specific quantities of the solvent and tobacco and relative amounts of the constituents in the tobacco and in the infusion have been indicated in the foregoing discussion, it is to be understood that said amounts are merely exemplary and are employed merely to simplify the tentative illustration. The general rule to be followed is that the standard infusion, before removing the tobacco treated therewith, contains the amount of any given soluble constituent originally in the tobacco multiplied by the ratio of the amount of solvent used to the amount of such solvent finally adhering to the tobacco when the latter has been removed from the solvent and the latter, as far as possible, pressed out of the tobacco.

Stated in another Way, the standard infusion shall be such that the amount of any given soluble constituent, e. g. nitrate, in the infusion prior to removing the tobacco therefrom is equal to the amount of said constituent originally in the portion of the tobacco under treatment divided by the ratio of the amount of liquid infusion retained by the tobacco to the amount of the infusion used for the extraction.

lVhat we claim is:

1. The method of treating tobacco which comprlses immersing the tobacco in an infusion containing the normally soluble constituents of the tobacco except nicotin, to permit the nicotin to go into solution, removing the tobacco, and pressing the infusion therefrom to leave an amount of liquid adhering to the tobacco sufficient to substantially preserve the normal amounts of the said soluble constituents except nicotin in the tobacco, the amount of the soluble constituents in the infusion before the tobacco is removed therefrom being substantially equal to the amount thereof originally in the tobacco multiplied by the ratio of the amount of the solvent used to the amount of such solvent finally adhering to the tobacco.

2. The method of treating tobacco which comprises immersing the tobacco in an infusion containing the normally soluble constituents of the tobacco except nicotin, to permit the nicotin to go into solution, removing the tobacco, pressing the infusion therefrom to leave an amount of liquid adhering to the tobacco sufficient to substantially preserve the normal amounts of the said soluble constituents except nicotin in the tobacco, the amount of the soluble constituents in the infusion before the tobacco is removed therefrom being substantially equal to the amount thereof originally in the tobacco multiplied by the ratio of the amount of the solvent used to the amount of such solvent finally adhering to the tobacco, and precipitating the absorbed nicotin from the infusion.

3. The method of treating tobacco which comprises immersing the tobacco in an infusion containing the normally soluble constituents of the tobacco except nicotin, to permit the nicotin to go into solution, removing the tobacco, pressing the infusion therefrom to leave an amount of liquid adhering to the tobacco sufficient to substantially preserve the normal amounts of the said soluble constituents except nicotin in the tobacco, the amount of the soluble constituents in the infusion before the tobacco is removed therefrom being substantially equal to the amount thereof originally in the tobacco multiplied by the ratio of the amount of the solvent used to the amount of such solvent finally adhering to the tobacco, and precipitating the absorbed nicotin from the infusion by a reagent containing the tannic acid radical,

4. The method of treating tobacco which comprises immersing the tobacco in an in fusion containing the normally soluble constituents of the tobacco except nicotin, to permit the nicotin to go into solution removing the tobacco, pressing the infusion therefrom to leave an amount of liquid adhering to the tobacco sufficient to substantially preserve the normal amounts of the said soluble constituents except nicotin in the tobacco, c

the amount of the soluble constituents in the infusion before the tobacco is removed therefrom being substantially equal to the amount thereof originally in the tobacco multiplied In testimony whereof We affix our signatures.

RALPH SAYRE. ELIAS YANOVSKY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

